A St. Petersburg municipal legislator said pop singer Madonna violated a controversial city law banning the promotion of homosexuality among minors at a concert and called for her or the company that organized the concert to be punished.

At a concert Thursday evening in the northern capital, Madonna called on the audience to raise pink wristbands many were wearing "to show your love and appreciation for the gay community," according to a video posted on the singer's YouTube account.

"We want to fight for the right to be free, to be who we are," she said on stage, according to Interfax. "I've traveled the world a lot and seen that people are becoming more and more intolerant, but we can change that."

During her performance, Madonna also bared her back to the crowd, revealing the words "No fear," and exposed her buttocks.

Local deputy Vladimir Milonov said that the concert was videotaped and that there were minors present, including 12-year-old children, and that therefore the law prohibiting so-called "homosexual propaganda" among minors had been broken.

"Madonna or the organizers need to be brought to justice," Milonov told Interfax. The news agency identified the concert's organizers as the company Petersburg Music Industry, or PMI.

Milonov authored the anti-gay bill, which drew outrage from human rights organizations in Russia and the West after its passage earlier this year. The law stipulates fines of up to 500,000 rubles ($15,700) for violators.

Close attention has been paid to Madonna's performances in Russia this week, since it was anticipated that she may express support for jailed members of punk band Pussy Riot — which she did at a concert in Moscow on Tuesday — and make statements backing gay rights in St. Petersburg.

On Thursday, a tweet by Deputy Prime Minister Dmitry Rogozin apparently calling Madonna a "whore" set off fervid discussion among bloggers, some of whom denounced the statement while others expressed agreement with it.

Rogozin, formerly an oppositional nationalist who has become a loyalist of President Vladimir Putin, suggested late Thursday on Facebook that the public may have misinterpreted the tweet.

"This is curious: Everyone understood the letter 'b' in my tweet monosyllabically, although it could have stood for such words as 'boginya' ['goddess'] or, for instance, 'ballerina.'"

Video of Madonna at a concert in St. Petersburg on Thursday calling on audience members to "show your love and appreciation for the gay community" by holding up pink wristbands.